Hypoxia-inducible factor 1-alpha promoter G-quadruplex (HIF-1α G4)

Hypoxia-inducible factor 1-alpha (HIF-1α) promoter G-quadruplexes are non-canonical DNA secondary structures formed by guanine-rich sequences within the HIF1A gene. These structures, characterized by stacked guanine tetrads stabilized by Hoogsteen hydrogen bonding, function as molecular switches that regulate the transcription of HIF-1α. In many solid tumors, HIF-1α is overexpressed and serves as a master regulator of the hypoxic response, promoting angiogenesis, metabolic reprogramming (the Warburg effect), and metastasis. Stabilizing these G-quadruplexes using small-molecule ligands inhibits gene expression by blocking the recruitment of transcription factors such as AP2 or disrupting the transcriptional machinery. This strategy aims to downregulate the HIF-1α pathway, thereby sensitizing tumors to therapy and inhibiting their adaptive survival mechanisms. While promising, the therapeutic use of G-quadruplex stabilizers faces challenges regarding target selectivity among different genomic G-quadruplexes and the potential for inducing broad genomic instability.

Other names

HIF1A G-quadruplexHIF-1 alpha promoter G4G4HIFHIF-1α S1 G-quadruplexG-quadruplexes in the HIF-1α gene

Stabilization of the G-quadruplex structure within the HIF-1α promoter or 5'UTR inhibits transcription and translation by blocking transcription factor binding and inducing conformational changes.